Progressive-feed processing apparatus

ABSTRACT

A long length product is conveyed by a conveyor to a propulsion mechanism into contact therewith. The product is gripped by a first conveyor line vise and cut at its tailing end side into a specified dimension. The product is advanced by the propulsion mechanism against the conveying force of the conveyor and then gripped by the first conveyor line vise and machined. A series of these operations are iterated. Finally, the product is advanced to a second conveyor line side, where it is gripped by a second conveyor line vise and subjected to final machining with the propulsion mechanism retreated. Instead of using a process of cutting to cut the leading end side of the product to a specified dimension, the leading end side of the product may be put into contact with the stopper and fed by referencing the leading end of the product.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for sequentiallyfeeding and automatically machining products having a long length. Morespecifically, the invention relates to a method and apparatus by whichvarious articles, especially long products, can be automaticallymachined in sequence to perform cutting, boring, end-notching, welding,or other machining processes at preset sites on the product, while theproduct is being advanced in the longitudinal direction.

2. Discussion of the Related Art

Steel materials such as shaped steel is often used as a structuralmaterial or the like. Generally, these types of steel materials are inmany cases, transported and carried in containing a length that islonger than necessary from the manufacturers. Therefore, it is commonpractice that the longer length steel materials are cut into necessarylengths by using torches or the like. Thereafter they are notched attheir end portions of each steel piece, followed by machining processessuch as boring at necessary locations.

However, since conventional approaches for machining have all beenmanual work, poor workability and longer working time are involvedthereby increasing the cost.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method forsequentially feeding and automatically machining long length articles orproducts such as shaped steel such that it is automatically fed andmachined for cutting in dimensions, boring, end-processing, or othermachining processes in sequence.

The method for sequentially feeding and automatically machining longlength products comprises a leading-end machining step, an intermediatemachining step, and a final machining step. The first and secondconveyor lines each have a vise in proximity to a machining area and areprovided on both sides of the machining area and so that the productsare successively and automatically machined at preset sites, while beingadvanced on the conveyor lines by a propulsion mechanism. Theleading-end machining step is a step for moving the propulsion mechanismto a preset initial position on the first conveyor line, and thentransferring the product toward the propulsion mechanism located on thefirst conveyor line. In this state, the product is gripped by the firstconveyor line vise and a leading end side of the product is cut to aspecified dimension. The intermediate machining step is a step releasingthe product from the vise and advancing the product to a preset distanceby the propulsion mechanism against a conveying force of the firstconveyor line so that the machined part of the product is fed to thesecond conveyor line while a to be machined target site of the productis set within the machining area. In this state, the unmachined part ofthe product is gripped by the first conveyor line vise and a presetmachining process is carried out on the to be machined target site.Further iteration then occurs for a series of the above describedoperations and for a preset number of times.

The final machining step feeds the tailing end of the product into themachining area by the propulsion mechanism against a conveying forcefrom the second conveyor line. Thereafter the product is gripped by thesecond conveyor line vise and with the propulsion mechanism havingretreated, the apparatus carryies out a preset final machining process.

Generally, long length products are often provided in sizes a littlelarger than their specified dimensions. Since the product is typicallyadvanced by referencing the tailing end of the product, this wouldadversely affect the advancing precision such that positioning precisionfor the machining target sites of the product could not be attained.Accordingly, advancing the product by referencing the leading end of theproduct makes it possible to set even shorter than specified productinto machining positions with high precision except for the machining ofthe tailing end.

Accordingly, a method for sequentially feeding and automaticallymachining long length products according to the present inventioncomprises an initial position setting step instead of the aforementionedleading end machining step. The initial position setting step is fortransferring the product by the conveyor lines toward the propulsionmechanism located on the first conveyor line until the product comesinto contact therewith. Thereafter a stopper is made to protrude intothe machining area, and the product is advanced by the propulsionmechanism against the conveying force of the first conveyor line untilthe product comes into contact with the stopper so as to plunge thestopper. In this state, the resulting position of the propulsionmechanism is taken as an initial position.

The product may be any long material without any particular limitationsas to shape, and applicable to, for example, the machining of shapedsteel. The type of machining may be any one of various machiningprocesses, including cutting, boring, notching, welding, and the like.

Further, according to the present invention, there can be provided anapparatus for sequentially and automatically machining a long lengthproduct at preset sites thereof after longitudinally advancing and thenstopping the product. The apparatus comprises first and second conveyorlines made from roller conveyors and provided on both sides of amachining area. The conveyors are capable of conveying the product in aforward direction and its reverse direction. The apparatus also includesa propulsion mechanism provided on the first conveyor line on theproduct feed side so as to contact the tailing end of the product andhaving enough propulsive force to advance the product forward toward themachining area against the conveying force of the conveyor line. Firstand second vises are also provided in proximity to the machining area ofthe first and second conveyor lines and they are able to grip theproduct. Further, a machining apparatus is provided in proximity to themachining area and is capable of carrying out a plurality of differenttypes of machining processes of the product. The apparatus also includesa controller which is capable of setting in advance the distancecorresponding to a plurality of to be machined target sites on theproduct and the types of machining processes for the individual targetsites. The controller can also drive and control the first and secondconveyor lines, the propulsion mechanism, the first and second vises,and the machining apparatus.

The reason that the conveyor lines are made from roller conveyors is toadvance the product smoothly against the conveying force of the conveyorlines. The rollers of the conveyor lines may be operated either in a waythat all the rollers are driven or in a way that part of them are drivenwith the remaining rollers being free.

Generally, when the product is machined on the conveyor lines, theproduct needs to be positioned not only in the longitudinal directionbut also in the widthwise direction. The longitudinal positioning can beachieved by starting to feed the product from a correct initial positionand then controlling the feed distance with a high precision. Thewidthwise positioning can be achieved by aligning the product widthwisewith the use of a widthwise adjustment mechanism comprising a pair ofpinching members and a drive mechanism. For example, the adjustmentmechanism can include a combination of an air cylinder, a hydrauliccylinder, a motor, and a feed screw mechanism. In this arrangement, ifthe roller conveyor line is tilted widthwise, the product placed on theline will move downward from the tilt by its own weight, so that theproduct can be widthwise aligned and positioned naturally. Thisarrangement allows the construction of the apparatus to be simplifiedgreatly.

The propulsion mechanism may be a system incorporating a rack and pinionor ball and screw or other like propelling means, which however wouldinvolve complex construction arrangements as well as increased cost.Therefore, it is preferable to use a drive motor and chains as thepropelling means. Favorably, the propulsion mechanism may contain ashock absorber mechanism capable of absorbing shocks due to contact withthe product.

The machining apparatus may be any one that can selectively perform aplurality of different types of machining processes. For example, themachining apparatus may be one which is provided with a plurality ofmachining tools such as a gas cutting torch, drill, and welding torch,and it can select one of them. However in terms of working efficiencyand space, the machining apparatus is preferably a machining robot thathas a plasma torch and that can move in three (XYZ) directions.

The controller is implemented by a microcomputer, computer, sequencer,or the like. It is necessary for the controller to be able to setmachining conditions according to the product as required.

In order to allow the product to be sequentially fed and machined byreferencing the leading end of the product, a stopper is provided thatcan emerge and be plunged in the machining area. The controller has thefunction of controlling and sensing the position of the stopper.

With the long length products placed on the conveyor line, the first andsecond conveyor lines convey the product backward or forward toward thepropulsion mechanism until the tailing end of the product is broughtinto contact with the propulsion mechanism previously set to an initialposition and thus it is positioned. Then, the product is gripped by thefirst conveyor line vise, and cut by the leading end side by themachining apparatus. This results in a product having a specifieddimension.

After cutting the product to the specified dimension, the vise is openedand the product is advanced by the propulsion mechanism against theconveying force of the first conveyor line. During this process, sincethe product is normally kept in contact with the propulsion mechanism byvirtue of the conveying force of the conveyor line, the product can beadvanced and positioned with a high precision by correctly controllingthe feed of the propulsion mechanism. The product is then advanced by apreset distance so that the machined portion of the product is fedtoward the second conveyor line, while the to be machined target site ofthe product is moved within the machining area. At this point, thepropulsion is stopped, and the long length product is gripped by thefirst conveyor line vise and subjected to the preset machining processby the machining apparatus.

After this, the operations of opening the vise, advancing and stopping,gripping by the vise, and machining occur. Upon reaching the finalmachining process, the product is fed to the second conveyor line sideby the propulsion mechanism so that the tailing end of the product isfed into the machining area. With the propulsion mechanism stopped, theproduct is then gripped by the second conveyor line vise. Then after thepropulsion mechanism retreats the final machining is carried out.

In the case where the machining process is carried out by referencingthe leading end of the product without setting the initial position ofthe propulsion mechanism, after the product comes into contact with thepropulsion mechanism, the stopper protrudes into the machining area andthen the propulsion mechanism is advanced so that the product comes intocontact with the stopper. This is where the then resulting productleading end position is taken as the initial position. From this pointon, the intermediate machining processes and the tail end machiningprocesses are carried out in the same manner as described above. With aproduct shorter than the specified dimension the final machiningprocesses may result in a fault but the intermediate machining processescan be carried out as previously set.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and features of the present invention willbe clearly understood from the following description with respect topreferred embodiment thereof when considered in conjunction with theaccomanying drawings, wherein the same reference numerals have been usedto denote the same or similar parts or elements, and in which:

FIG. 1 is a schematic side view showing a sequential feed automaticmachining apparatus for long length product according to an embodimentof the present invention;

FIG. 2 is a side view showing the construction around the centralportion as well as the propulsion mechanism in the apparatus;

FIG. 3 is a side view showing the construction around the terminal endof the first conveyor line as well as the propulsion mechanism in theapparatus;

FIG. 4 is an end view showing the front construction of the starting endside or loading side of the first conveyor line;

FIG. 5 is a front view showing the relationship between the firstconveyor line and the propulsion mechanism;

FIG. 6 is an side view showing the stopper in the apparatus;

FIG. 7 is a flow chart diagram showing the processing flow of thecontroller in the apparatus; and

FIG. 8 is a partial side view showing a second embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Herein below, the present invention will be described in detail based onthe embodiments thereof as illustrated in the accompanying drawings.FIGS. 1 through 6 show a sequential feed automatic machining apparatusfor long length product according to an embodiment of the presentinvention. In the drawings, first and second conveyor lines 10, 11 aredisposed in straight line on both sides of a machining area A, andintermediate auxiliary rollers 12, 13 are retractably provided betweenthe two conveyor lines 10, 11.

In the first and second conveyor lines 10 and 11, a plurality ofconveyor rollers 101, 111 are longitudinally spaced from one anotherwith specified intervals and rotatably held to conveyor frames 100, 110having specified lengths. For example, the feed-in side first conveyorline 10 can be 15 m and the feed-out side second conveyor line 11 can be12 m. Out of the plurality of conveyor rollers 101, 111, those at therear end and the front end as well as some of those in the middle havesprockets 102, 112 attached on both ends and further have drive chains103, 113 stretched over them.

Each conveyor roller 101, 111 on the starting end side, i.e. themachining area A side of the first conveyor line 10 and on the terminalend side, i.e. the machining area A side of the second conveyor line 11,has a drive sprocket 104, 114 attached thereto. The drive sprockets 104,114 are connected to the sprockets of transfer motors 105, 115 by chains106, 116, so that the product W placed on the lines can be transferredalong their length.

In the first and second conveyor lines 10, 11, the conveyor rollers 101,111 are tilted widthwise by a specified angle, for example 15°, withrespect to the vertical direction as shown in FIGS. 4 and 5. As aresult, the product W placed on the lines will slide downward along thetilted surface by its own weight so as to be aligned widthwise.

The first and second vises 14, 15 are provided in proximity to themachining area A on the terminal end side of the first conveyor line 10and the beginning of the second conveyor line 11, respectively. Thesefirst and second vises 14, 15, although not shown in detail, are fixedat the side that is tilted down, and on the other side, each comprise apair of widthwise slidable claws and a hydraulic or air cylinder thatslides the other claw so that the product W can be gripped and fixed.

The intermediate auxiliary rollers 12, 13 are so constructed that acentral part of a link having a front end roller is held to the conveyorframe 100, 110, and the rod of the hydraulic cylinder attached to theconveyor frame 100, 110 is connected to the other end of the link. Thus,the intermediate auxiliary rollers 12, 13 can emerge into the machiningarea A from below the conveyor lines 10, 11.

A stopper 16 is provided in the machining area A. As shown in FIG. 6, apair of front and rear mounting brackets 160, 161 are attached on thelower surfaces of the conveyor frames 100, 110, while a guide 162 isprovided in the front side mounting bracket 160. In the guide 162 isdefined a horizontally extending guide recess into which one slide pin163, 164 is slidably accommodated. The slide pins 163, 164 are attachedto the base portion of an arm 165. The upper part of the rear half ofthe guide recess is opened so that the slide pin 164 can withdrawtherethrough. At the rear edge of the mounting bracket 160 is defined agenerally arc-shaped guide edge 166 for upwardly guiding the slide pin164 that has been withdrawn through the guide recess. Thus, the arm 165is able to exert actions of advancing and retreating in the forward andbackward direction while also swinging in the up and down direction (seearrows A and B in FIG. 6).

On the other hand, a hydraulic cylinder 167 is swingably attached to therear side mounting bracket 161. The rod of the hydraulic cylinder 167 isconnected to the lower end of the arm 165 to drive the arm 165. The arm165 can retreat from the contact position where it has protruded upwardof the conveyor lines 100, 110 and within the machining area A toward aretracted position which is below the conveyor lines 100, 110. The arm165 then swings downward, thus being plungeable without moving theproduct W into contact therewith. At the end of the arm 165, apositioning member 168 is provided and the positioning member 168 isequipped with a rod for turning a limit switch 169 on and off.

A propulsion mechanism 17 is mounted on the terminal end of the firstconveyor line 10. This propulsion mechanism 17, as shown in FIGS. 2 to5, has propulsion sprockets 170 attached on right and left both ends ofthe starting end conveyor roller 101 of the first conveyor frame 10 andon the starting end side right and left of the conveyor frame 100. Apropulsive chain 171 is stretched between the front and rear propulsionsprockets 170, and both edges of a boat 172 are fixed between the tworight and left propulsive chains 171, 171. The boat 172 is placed on theconveyor roller 101.

A drive motor 173 is mounted below the terminal end of the conveyorframe 100, and a drive sprocket 174 is mounted to the rotating shaft ofthe drive motor 173. The drive sprocket 174 is coupled with the startingend side propulsive sprocket 170 by a chain 175. A rotary encoder 176 ismounted on the drive motor 173 so that the propulsion distance can becomputed from the number of revolutions of the motor.

A power cylinder 177 is mounted on the boat 172 by brackets, and thepower cylinder 177 transfers the rotation of the brake equipped motor tothe ball and screw with the speed reduced by gears to thereby stroke therod. Besides, it contains a propulsive force detection spring unit whichcomprises, in combination, two types of prepressed conical disc springswith different spring constants and a limit switch so that any shocksgiven to the rod can be absorbed and so that the rod can be held in aspecified stroke position.

A pushing bar 178 is mounted on the boat 172, and fixed at the end ofthe rod of the power cylinder 177. An oilless bushing is interposedbetween the pushing bar 178 and the boat 172 so that the pushing bar 178is slidable.

A trolley duct 18 is mounted at an upper edge of the conveyor frame 100on the upper side of its tilt, over the entire longitudinal length, sothat the power cylinder 173 can be powered via the trolley. Asubstantially upright auxiliary roller 19 is provided at an upper edgeof the conveyor frame 100 on the lower side of its tilt so that itsupports the upper part of the large size product W aligned widthwise byits own weight.

A machining robot 20 is provided in proximity to the machining area A.The machining robot 20 has a plasma torch at the front end of its armthat is movable in the three (XYZ) directions. A controller 21 isimplemented by a microcomputer, and drives and controls the first andsecond conveyor lines 10, 11, the intermediate auxiliary rollers 12, 13,the first and second vises 14, 15, the stopper 16, the propulsionmechanism 17, and the machining robot 20.

Next, the process of machining is explained with reference to FIG. 7.FIG. 7 shows the flow of computation processes in the controller. Forsequentially feeding and machining a long product W such as shapedsteel, the controller 21 is first turned on, and conditions are set inthe controller 21 corresponding to the product W (step S1). Theconditions include specifying whether or not the machining reference isthe tailing end or leading end of the product, the initial position ofthe propulsion mechanism 17, the machining position of the product, andthe type of the machining.

Subsequently, when the product W is placed on the second conveyor line11, the system is activated. Then if the machining reference is for thetailing end of the product, the propulsion mechanism 17 is moved to theinitial position, in which state the first and second conveyor lines 10,11 are driven (steps S2, S3). The product W is transferred toward theterminal end of the first conveyor line 10. When the product W comesinto contact with the pushing bar 178 of the propulsion mechanism 17,the tailing end of the product W can be positioned at the initialposition. Then, the product W is gripped by the first vise 14 and themachining robot 20 operates to cut off the leading end side of theproduct W. Thus, the product W is made to the specified dimension (stepsS4 to S8).

With the product W machined into the specified dimension, the first vise14 is opened and the propulsion mechanism 17 propels the product Wforward (step S10). In this process, because the product W is normallykept in contact with the pushing bar 178 by the conveying force of thefirst conveyor line 10, it can be advanced with high precision. Theleading end side of the product W is then fed toward the second conveyorline 11. With the product W advanced to a predetermined distance, thepropulsion mechanism 17 is stopped from advancing (steps S11, S12),whereas the product W is subject to the conveying force of the first andsecond conveyor lines 10, 11 so that the product W will not advancefurther by its inertia, but will stop correctly at the desired position.

Coming to a stop, the product W, is gripped by the first vise 14, inwhich state the machining robot 20 performs the required machiningprocess that have been input to the controller 21, such as cutting,boring, notching, or welding (steps S13 to S15). Likewise, according tothe conditions input to the controller 21, the operations of opening thefirst vise 14, advancing and stopping, gripping by the first vise 14,and machining are continued, by which the intermediate part of theproduct W is machined (steps S10 to S17).

After the intermediate machining of the product W, when the trailing endof the product W becomes the next site to be machined, the propulsionmechanism 17 is now an obstacle for the gripping operation of the firstvise 14. Therefore, the propulsion mechanism 17 in turn is advanced sothat most of the trailing end side of the product W is fed to the secondconveyor line 11. The trailing end of the product W is set within themachining area A, and the propulsion mechanism 17 is stopped (steps S18to S20). With the propulsion mechanism 17 stopped, the product W isgripped by the second vise 15 on the second conveyor line 11, and thepropulsion mechanism 17 retracts (steps S21, S22). When the machiningprocess is to be iterated under the same conditions, the propulsionmechanism 17 is preferably retracted to the initial position. Finally,the trailing end of the product W is subjected to the machining processinput to the controller 21. Then, the second vise 15 is opened, whilethe second conveyor line 11 is rotated reverse, so that the product W isfed out (steps S23 to S26).

In the case where the machining is carried out by referencing thetrailing end of the product W without setting the initial position ofthe propulsion mechanism 17, the first and second conveyor lines 10, 11are driven so that the product W is first brought into contact with thepropulsion mechanism 17. Thereafter, the stopper 16 on the secondconveyor line 11 protrudes into the machining area A (steps S27 to S29).

Next, the propulsion mechanism 17 is advanced so that the leading end ofthe product W is brought into contact with the stopper 16, andthereafter the stopper 16 is plunged inward. Then, since the correctposition of the stopper 16 is previously known, the leading end of theproduct W can be positioned. With this position taken as the initialposition, the machining target position input to the controller 21 iscorrected. Subsequently the intermediate machining processes and thefinal machining processes are carried out by referencing the determinedinitial position (steps S10 to S26). In this case, the sequential feedautomatic machining may be applied not only to product W which is longerthan the specified dimension but also a product W shorter than thespecified dimension. However, in the case of a product W that is shorterthan the specified dimension, the final machining process would resultin a fault but otherwise the machining process can be carried out aspreviously set.

FIG. 8 shows a second embodiment of the present invention where thepropulsion mechanism 17 is modified. In the foregoing embodiment, thepower cylinder 177 is mounted on the propulsion mechanism 17 for theabsorption of shocks due to contact with the product W and duringpositioning of the product W. However, with this arrangement, the costwould increase since the trolley duct 18, which is the power supplyequipment for the power cylinder 177, as well as a U-shaped channel formounting the trolley duct 18 are required, result in a complicatedconstruction. This being the case, the pushing bar 178 is supported by abracket 180 with a relatively hard rubber 179 interposed therebetween.This assembly is attached to the boat 172 in order that shocks due tothe contact with the product W will be absorbed and, further the hardrubber 179 will be restored to its original state so that the product Wcan be positioned with a high degree of precision.

Therefore, according to the present invention, products having a longlength can be transported and carried in from steel manufacturers or thelike, and while they are being cut, they can be subjected to desiredmachining processes. This eliminates the need of first cut the productand thereafter machine it as would be involved in the prior art. Thus,the efficiency of the apparatus can be dramatically improved so as toreduce the working time and, as a result, significant cost reduction forthe operation can be realized.

It is to be understood that although the present invention has beendescribed with regard to preferred embodiments thereof, various otherembodiments and variants may occur to those skilled in the art, whichare within the scope and spirit of the invention, and such otherembodiments and variants are intended to be covered by the followingclaims.

What is claimed is:
 1. An apparatus for sequentially and automaticallymachining long length products at preset sites after advancing theproduct longitudinally and stopping the product, comprising:first andsecond conveyor lines including roller conveyors, each first and secondconveyor line being provided on opposite sides of a machining area andcapable of conveying the product with a conveying force in both aforward and a reverse direction; a propulsion mechanism disposed on thefirst conveyor line on a product feed-in side so as to be engageablewith a tailing end of the product, said propulsion mechanism havingsufficient propulsive force to advance the product forward against theconveying force of the said and second conveyor lines; first and secondvises provided in fixed proximity to the machining area of said firstand said second conveyor lines, said first and second vises beingcapable of gripping the product; a machining apparatus provided inproximity to the machining area, said machining apparatus being capableof performing a plurality of different types of machining on theproduct; and a controller for setting at least advancing distancescorresponding to a plurality of machining target sites on the productand for setting the types of machining for individual machining targetsites of the product, said controller further driving and controllingsaid first and second conveyor lines, said propulsion mechanism, saidfirst and second vises and said machining apparatus.
 2. An apparatus asdefined in claim 1, further comprising a stopper provided in themachining area, said stopper having an extended position and a retractedposition, and said controller sensing and controlling said stopper. 3.An apparatus as defined in claim 1, wherein conveying surfaces of saidfirst and second conveyor lines are tilted widthwise so that the productplaced thereon will be aligned widthwise by its own weight to therebyposition the product widthwise.